Sunday, July 6, 2014

Bletchley Park, England

Ron here with a guest post on Mom's blog. I am working in London, England right now. I had a Sunday free so I decided to go see Bletchley Park, about an hour northwest of London. I've wanted to see this for years. I would not be surprised if you have never heard of it. It is fairly new as a publicly accessible museum.
The Original Mansion
Bletchley Park was the central site of the United Kingdom's Government Code and Cypher School (GC&CS), which during the Second World War regularly penetrated the secret communications of the Axis Powers – most importantly the German Enigma and Lorenz ciphers. The official historian of World War II British Intelligence has written that the "Ultra" intelligence produced at Bletchley shortened the war by two to four years, and that without it the outcome of the war would have been uncertain.

This place was the was similar to Manhattan Project at Los Alamos, New Mexico during WWII, which produced the atomic bomb. Except at Bletchley, the British managed to decipher Axis signals. Most significantly, they used the best minds in the UK to break the German Enigma machine. This signals encryption machine was thought by the Germans to be unbreakable. They were wrong.

At Bletchley, the UK gathered the best minds in the country, swore them to top secrecy, and let them apply their genius on breaking the signals of the Germans, Japanese, and Italians. Most of the people that worked there never spoke to anyone of their service. They were not allowed to. It wasn't until the last 20 years that this place became declassified.

What came out of Bletchley Park, thanks to the efforts of Alan Turing, was the world's first electronic programmable computers.  Turning had figured out how to use the brute strength of computers to implement methods and algorithms of his design to turn the art of cryptology into in industrial scale that allowed the Allies to read the German war plans in almost real time by D-Day.

This place is also the birth of the modern computer. Everything done by computers today, including the one you are using to read this post, started here.

The most famous person associated with Bletchley Park is Alan Turing. He was a young math genius from Cambridge. He came up with the methods that cracked Enigma, and exploited the weaknesses in how the Germans implemented it. He also founded the theories that the modern computer systems are built in. He died of suicide at age 41, after the war. He was eccentric, and he was also gay, which at the time was illegal. After the war he was prosecuted for being homosexual and sentenced to chemical castration. He did the castration, but his criminal conviction lost him his security credentials and his job. His life and reputation was destroyed, so he drank cyanide.

Turing's Office
It is tragic that the one man who almost single handily gave the Allies a strategic advantage over Germany and Japan, who was trusted with Britain's most closely guarded military secret, and who saved thousands and thousands of lives and altered the course of history was treated like this. He could never speak of his service. And he never did. It really wasn't until the 1990's that the truth came out. It wasn't until 2013 that he was formally pardoned and his named cleared.

Statue of Alan Turing at the museum
A note from Google on why Bletchley Park matters
So that's the background. Now Bletchley Park is a museum dedicated to the work they did here. After WWII all of the computers they built were ordered destroyed, and the facility fell into disrepair. It wasn't until recent history and the efforts and the American and British computer industry that it was restored. Many American IT and Internet firms, such as Google, have helped out with large donations to get the project going.

Sorry about the shadow. My flash isn't strong enough to cancel it out.
I hope this doesn't bore you. I find it fascinating. It serves as an excellent illustration of the fragility of data systems and how seeming small errors can be exploited as major flaws. At the museum, they give examples of this.

They tell the story of one bored German Enigma operator who accidental gave Blechley the breakthrough they needed to crack Germany's newer, most secure, Enigma machines. The German, for reasons unknown, send an encrypted message of nothing but the letter "L". He was probably testing it, or training. But this mistake allowed the British to construct the encryption key used, and from that, reverse engineer the new Enigma. Once they did that, they were able to build specialized computers called "Bombes" designed by Turing to decrypt the German signals.

Other mistakes that were exploited by Bletchley were panicked German officers who send the same message over two or more systems. They would send the message over a less secure, compromised, network. That would give Bletchley the clear text which allowed them to construct that day's encryption key. That in turn would let them read all of the German signals that day.

It was small errors like this that they learned to exploit, day in and day out, for years. They learned how certain German operators likes to use their girlfriend's name, or a German swear word, as the initial Enigma settings. Or how certain German officers also used the same greeting in all of their messages. These little mistake would reduce the effectiveness of their encryption by orders of magnitude, allowing them to decode them in almost real time.

They have a collection of Enigma machines on site. I've only seen one before, owned by the NSA. They were recruiting at an event I was attended and they had in their booth to get curious people like to me stop by and talk to them.

The museum also has a collection of Enigma Machines.
They have rebuilt one of the Bombe's
If you find yourself in the UK and have a day free, I recommend that you stop by and visit. I think it is worth it.


  1. Thanks for the post. I am so glad to see that you are not working every minute you are there. MOM

  2. very interesting
    june sherman